1. Field of the Invention
The present invention relates to a display apparatus equipped with a panel substrate having a panel, a so-called active matrix type display panel, composed of a plurality of pixels connected to cross points between a plurality of data lines disposed successively along one direction and a plurality of gate lines disposed successively along another direction.
2. Description of Related Art
A display panel for displaying images by an active matrix scheme has gate lines each having a switch for selecting pixels in a horizontal line and data lines for writing video data from a vertical direction. Each data line is connected via a data line driver to a signal line over which video data is transmitted from a control driver. The data line driver selects a data line to which video data to be transmitted via the signal line is supplied.
A display apparatus including the display panel constructed as above, for example, a direct-view type liquid crystal display panel using amorphous silicon, has one data line corresponding to one signal line.
In contrast, a gate line driver for controlling selection of a gate line and the above-described data line driver can be assembled in a liquid crystal display panel using low temperature polysilicon, high temperature polysilicon, or single crystal silicon, or in an organic EL display panel. In the display panel assembled with these drivers, video data transmitted by one signal line via the data line driver can be distributed to a plurality of data lines. With this display panel, pieces of video data corresponding in number to the number of signal lines can be written at the same time in pixels connected to the data lines.
In the display panel having the structure described above, techniques for mitigating degradation of visual characteristics such as motion blur inherent to moving image display are widely used in recent years, which the number of frame rewrite operations per unit time of a display apparatus is increased, so that forward and backward frame images in a time axis direction is interpolated into each increased frame or a black image plane is inserted to each increased frame.
Consequently, there is a tendency that a frame rate representative of the number of frames to be rewritten per one second is changed from an existing 60 fps to 120 fps or higher for a display panel of an active matrix type or the like such as a liquid crystal display panel and an organic EL display panel including a transmission type and a reflection type. In the following, the existing 60 fps driving scheme is called a 60 Hz driving scheme, and a driving scheme not lower than 120 fps is called a high frame rate (HFR) driving scheme.
Since there are demands for display panels of both the 60 Hz driving scheme and HFR driving scheme, an issue arises in the necessity of developing the display panels compatible with both the 60 Hz driving scheme and HFR driving scheme independently.
One approach to operating a display panel designed for driving schemes according to a plurality of frame rates is to increase twice of the number of already-existing data line drivers of the 60 Hz driving scheme in order to make compatible with the HFR driving scheme or to switch an operation frequency at two stages for already-existing data line drives. This approach is, however, difficult to be achieved in terms of cost.
As an approach to operating a display panel designed for a plurality of driving schemes having different consumption powers at the same frame rate, for example, Japanese Unexamined Patent Application Publication No. 2001-222266 describes a display apparatus which achieved a reduction in a consumption power by switching display areas by using K gate lines among N gate lines for a displaying state, and by using remaining (N-K) data lines for a non-displaying state.